1. Field of the Invention
The present invention is directed to a method for reading out a storage luminophore plate, of the type used to store an image produced in a medical x-ray system.
2. Description of the Prior Art
The scanning of storage luminophore plates with a stimulation laser is known. The area employed for imaging is thereby scanned point-by-point along lines. The speed of this scanning is limited by the minimum integration time required for each picture element, this integration time being prescribed by the decay time of the storage luminophore. The readout time for the entire image format given current devices amounts to 1-2 minutes and is actually too slow for modern hospital operation. Moreover, such a device for line-by-line punctiform scanning with a mechanically guided laser beam, and readout with a photo multiplier has a large structure. Due to its large structure, this device cannot be integrated into a medical X-ray system but must be erected separately therefrom, which requires space and room. The physical transport of the storage luminophore plate with corresponding time delay and risks of mix-ups, etc., between the actual X-ray exposure and the digitization on the basis of the readout of the storage luminophore plate with the device and the transmission of the data are disadvantages associated with this type of device.
German OS 195 06 798 discloses an alternative to the aforementioned scanner device. German OS 195 06 798 discloses a device for reading out storage luminophore plates wherein a contact pressure means for a storage luminophore film is provided and with which the storage luminophore film can be pressed planarly against a counter-plate and fixed. An aSi:H detector matrix is arranged at the opposite side of the counter-plate. This detector matrix and the storage luminophore film thus can be aligned in substantially parallel planes relative to one another via the contact pressure device.
A detector matrix as disclosed in German OS 195 06 798 is expensive to manufacture and, due to the multitude of detector elements, the risk of an outage of individual detector elements is relatively high, which degrades the signal output.
U.S. Pat. No. 4,694,163 discloses a device for readout of a storage luminophore plate with which the storage luminophore plate can be subjected to a sag. This device has a roller that can be adjusted from a first position, in which it has no contact with the storage luminophore plate, into a second position in which it effects a sag of the storage luminophore plate. A good and constant guidance of the storage luminophore plate is to be assured due to the sag of the storage luminophore plate.